Precast floor or roof slab



Feb. 5, 1935. H. F. YOUNG 1,990,157

' PRECAST FLOOR OR ROOF SLAB Filed Sept. 21, 1953 ATTORNEYS.

1,990,151 I iRECAST'FLOOR onnooF SLAB a oward Young; Kalamazom-Michs Leonie Young administratrix of said-.HowardF'Young, deceased Apnlicatidn 'se t mber'zi, 1933, Serial No. 690,299 130 m. (01. 72-,-68 J r s This application is acontinuation in part of with "my oo-pending. apphgation g m N my application SerialNo. 641.3621fil8d November 532,837, filed April 25', 1931., This joist comprises 5, 1932; forpre -cast ,floor or roof slabs. The ina joist pro-cast from concrete a d reinforced by vention relates to those of my co-pending applie metal reinforcements. The concrete is prefcations Serial No. 532,835 filed April 25, 1931 erably'what is known as porous concrete which 5;

and Serial No. 532,837 filed April 25, 1931. The may be made with. a gravel aggregate or, an invention has for itsv objects: aggregate of vitrified, aerated clay or cinder or First,;to provide a simple and efiective concrete any product known commercially as a light or cement floor or roof construction in which weight aggregate.' The use oiordinary concrete pre-cast joists-and pro-cast slabs are utilized; with a usual gravel aggregate is equally possible, 10..

Second, to provide such; a construction in and has only the possible; disadvantage of inwhich the slabs and joists are joined together creased weight; v V with a-cement-to-cement bond toformxa mono- 2 is a longitudinal reinforcing barand 3 are lith without the use of any projecting steel ortension reinforcing bars of suitablemetal. i-are other reinforcements to act asbonding members. metal shear members; The members 2.13 and 4 155' Third, to provide such a construction that may may be welded in the 1')ositions shown in Fig." 1.' beeasily, cheaply and quickly put upend in 5'are' pre-cast concrete ,slabs-thatare preierably which the partsmay be made away from the approximately twelve incheswide, from oneto building site. which greatly reduces the cost. two inchesthick and tenie'e't in" length. These Fourth, to provide such a floor orroofin which dimensions need not necessarily be followed but 20 pre-cast joistsand slabs are joined together with are a suitable size for easy handling. s a cement -to-cement bond to provide T beam 6 a lo g di al metallic reinforcing bars in construction which the pre-castslabs-act' as said s1abs. The slabs canbe reinforced by any compression members. p suitable mesh or other reinforcing as. desired. V ,Fifth, toprovide a pre-cast slab of concrete or The edges of the slabs are beveled as at 8 or may 25 similar material of suitable form to be joined to beshouldered as at 9 (see Fig. 4),;to; provide a other slabs and to joists. 1 recess between the" slabs for the reception of Other objects and advantages pertaining to bonding cement.- Any suitable shaping to mm 3 details of construction willlappear irom the desuch a recess can be used. The-'slabs '5' are dis my invention is illustratedin the accompanying shown; andare-joined thereto-by -a cement'bond drawing, jn whiche r ,1. l 10 which maybe buttered on the heads o'f the Fig. 1 is an isometric fragmentary perspective joists or may be applied in any suitab1e-' way. view of a floor or roof made accordance with It is possible to place the slabs on thejolstsand my i v n n, showing e teps during n uct trowel or spray the cement to form a shoulder 3 tion and a portion in substantially finished form, 11 which embraces the sides ofthe heads of the a portion of the finishing beingfbroken joist 1 and the under side of the slab to form a away to show disposition and. arrangement of complete bonding *or considerablesection as the various parts. 7 7 necessary.

scription to'follow'. Apreferredembodiment of posedfover and transversely of the joists" has Fig. .2-is a detail transverseisection through 12 are reinforcing metallic rods -disposed.

one of the joists and .the fioor showing the artransverselyof the slabs for reinforcing and load rangement of theslabs and thebondingbetween distributing and also to prevent shrinkage. In the slabs 'andthejoists. T some constructions iti's desirable to place nega- 3 is a section through a portion of the tive reinforcing members 13 across the slabs as floor parallel to a joist showing the arrangement shown in"Fig. 5. These "rods '13 are disposed of the slabs andthe finishingmortarg-j. across girders or/wall supports and when bonded .Fig. 41s a similar view showing asli' htly modiin positionr provide ,cantilever support ;for the fled type of slab t 1 f construction and produce continuity as will be Fig- 5 is a detail view ,parth' in section taken explained. Such negative reinforcing, are transversely through, a girder and through one not necessary in all constructions; but are desire 50 of the joists showing the continuity obtained by able where an especially strong construction is my invention. 7 I desired. v The parts will be identified by their numerals 14 is a finishing mortar coat overlying the slabs of reference which are the same in all the views; and embracing the rods .12 and 13. also 5 1 indicates a pre-cast joist made inaccordance into the recesses between the slabs to'bond'the the coating 14 if it is desired to lay a wood fioor,-i.,

such as 16, thereover.

It will beeasily understood v binds the slabs 5 to the joists l to form "a'ceinentto-cement bond that is ofconsiderable strength and which binds the slabs to the joists to give a T-beam effect. The mortar .14 running into the recess between the slabs, or the grouting placed between the slabs before pouring the'finishing layer, binds them togetherwitha .cement-to-ce ment bond.- The mortar 1.4 binds the 'rods12 and '1 13 to theslabs. The whole construction is then monolithic in its nature. u 7

I have described the vconstruc't'ion as of concrete and I..,do. not Wish, to be limited to ordinary Portlandcement concrete by use of the term cement. Anyccmentitious materiah such as gypsum'orithe like jcould be used. j

.I have described the use of a' light weight aggregate to produce a porous, construction, and al-.

though this is the preferred form, tests have,

shown that any form of concrete having what is trm d'abs rp ive qualities could be used, or any type of cement thatcan be bonded with'a cement:

to-cementbond. Although' it is most desirable that the .cementitious material used i n the joists,

the slabsand the mortar besubstantially similar, it is possible to bondic'er'tain dissimilar cements togetherand I do not'wish to'be confinedto the use of similar cementitious material atall times.

By using'the negative reinforcing. rods 13,;it is possible to obtain cantilever support overgirders or wall supports and-the bonding of the cement to the joists other'parts produces what is known as continuity. The bar13 or, to a certain extent,,even the. bars 12 become tension members when stretched over a support; The tension is transferred from the rod 13 to the tension member 3 of the joist by the shear members} and the concrete bonding, thus providing for .tensionof the supports as it is needed,running continuously through, the tension, of rthejoists. In such a construction-the girder is preferably. poured to embrace theend of; thejoist and maybe integral with ,the covering 14, as is illustrated in Fig. 5; It hasheretoforebeen thought that a bonding such :as I have described between-the joists and the slabs and between the adjacent slabs could not be: utilized, and constructions attempting to use pre-cast concrete members have provided metal extensions to be cast in cement to provide for bonding. By using construction it is unnecessary to provide such members, and I am able to obtain a complete monolith in which the slab becomes thev compression member inaT-beam construction. This is'acc'omplished with 'a' saving of reinforcing material' and with a saving of labor in arranging for the projectingreinforcements, which-also greatl facilitateshandling the concreteslabs-and joists After the coating 14 is poured or spread on the tops ofthe slabs and embracing the rods 12, the ends of .the slabs are held up by the load disthatthe mortar lo' tributing reinforcing rods 12 and the bond formed between the coating and the slabs.

It is possible to, use this slab on steel or other suitable joists. This would give a completely monolithic slab as can be formed with a poured cast concrete joists having longitudinal reinforcing tension members cast therein and having wall or girder supports, with the abutting ends of the joists joined by a cement-to-cement bond,- pre-cast ireinforced concrete slabs overlying said joists and united thereto and to one another by a cement-to-cement bond, shrinkage and slab reinforcingrods overlying said slabs transversely negative reinforcing rods extending transversely of said supports, a concrete mortar top finishingoverlyin'gsaid slabs and mbrace ing said rods'whereby said rods'are bound' to said slabs and whereby said negative reinforcing rodsj provide cantilever support. 3 2. A concrete floor 'orroof formed with-precast concrete joi'stshaving longitudinal reinforce ing tension members cast thereinand having wall or girder supports, with the abutting ends of the joists joined by a cement -to-cement bond; pre-cast concrete slabs overlying said-.jois'tsandunited thereto and to one another by a cementto-cement bond, shrinkage and slab reinforcing rods overlying said slabs transversely, a concrete V mortar top finishing overlying said slabs and to said slabs. if 4 3 A concrete floor or roof formed withprecast concrete'joists, pre-c'ast reinforced concrete,

slabs overlying said joists and united thereto and to one another by a cement to-cement bond,

shrinkage and slab reinforcing rods overlyingsaid slabs transversely, a concrete mortar top finishing overlying said slabsand providing a cement-to-cement bond between said slabs and embracing said rods whereby saidrods are bound to said slabs to provide continuity,"-whereby a onolith is formed. p 1

4L 'A-co'ncrete fioor orroojf; formed with precast concrete joists, 'pre-castconcreteslabs overlying said joists and united thereto'and to, one another by "a cement-to-cement; bond, shrinkage and slab reinforcing rods overlying saidslab's transversely, a concrete mortar top finishingoverlying said slabs and embracing saidrods whereby said rods are'bound to said slabs to provide continuity, wherebya monolith is formedg V 5, A concrete floor or roof formed with precast concrete "joists, pre-cast reinforced concrete their contacting surfaces with a. mortar iloint forming a 'cementtocement bond, said slabs having their abutting edges. whose direction "ear-ltends transversely to the direction: of the joists joined withIa mortar joint forming a cement to cement bondfand a concrete mortar top finishing overlying said "slabs wherebyafr beam monolith without projecting metallic C reinforcement penetrating the joints between the pre-cast members is formed in which the slabs form the prin-, cipal compression member and the joists the principal tension members.

6. A concrete floor or roof formed with precast concrete joists, precast concrete slabs'overlying said joists and united thereto at their conembracing said rods wherebysaid rods are bound tacting surfaces with a mortar joint forming a cement-to-cement bond, said slabs having their abutting edges whose direction extends transversely to the direction of the joists joined with a mortar joint forming a cement to cement bond, a concrete mortar top finishing overlying said slabs, whereby a T-beam monolith without projecting metallic reinforcement penetrating the joints between the pre-cast members is formed in which the slabs form the principal compression member and the joists the principal tension members.

7. A concrete floor or roof formed with precast concrete joists, pro-cast reinforced concrete slabs overlying said joists and united thereto at their contacting surfaces with a mortar joint forming a cement-to-cement bond said slabs having their abutting edges whose direction extends transversely to the direction of the joists joined with a mortar joint forming a cement to cement bond, whereby a T-beam monolith without projecting metallic reinforcement penetrating the joints between the pre-cast members is formed in which the slabs form the principal compression member and the joists the principal tension members.

8. A floor or roof formed with joists pre-cast from a cementitious material, slabs pre-cast from cementitious material, and overlying said joists and united thereto at their contacting surfaces by a mortar comprising a cementitious material to form a T-beam monolith without a projecting metal reinforcement penetrating the joints between the pre-cast members and in which the slabs form the principal compression member and the joists the principal tension members.

9. A floor or roof formed with joists pre-cast from cementitious material, slabs pre-cast from cementitious material and overlying said joists and united to each other by a cement mortar, and united to said joists at their contacting surfaces by a cement mortar embracing the heads of said joists to form a T-beam monolith in which the slabs form the principal compression member and the joists the principal tension members.

10. A floor or roof formed with pre-cast concrete joists, pre-cast concrete slabs overlying said joists and united to each other by a cement mortar and united to said joists at their contacting surfaces by a cement mortar embracing the heads of said joists to form a T-beam monolith in which the slabs form the principal compression member and the joists the principal tension members.

11.'A concrete floor or roof structure formed with pre-cast concrete joists andpre-cast con crete slabs overlying said joists and united thereto at their contacting surfaces solely with a mortar joint forming a cement to cement bond,

said slabs having their abutting edges whose direction extends transversely to the direction of the joists joined solely with a mortar joint forming a cement to cement bond to form. a

T-beam monolith in which the slabs form the principal compression member and the joists the principal tension members.

12. A concrete floor or roof structure formed with pre-cast concrete joists and pre-cast con crete slabs overlying said joists and united thereto at their contacting surfaces solely with a mortar joint forming a cement to cement bond to form a T-beam monolith in which the slabs form the principal compression member and the joists the principal tension members.

13. A concrete floor or roof structure formed with pre-cast concrete joistsand pre-castconcrete slabs overlying said joists and united there-,-

to at their contacting surfaces with a mortar joint forming a cement to cement bond, said slabs lying in staggered relation and having their edges whose direction extends transversely of the direction of the joists abutting and joined by a mortar joint forming a cement to cement bond to form a T-beam monolith in which the slabs form the principal compression member and the joists the principal tension members.

HOWARD YOUNG. 

